Question

5. A car travelling at 60 km/h uniformly retards for 10 s and reaches a velocity of 45 km/h. Find the retardation (Ans. 042 m​

Answer 1

• initial velocity = u = 60 km/h = 60 × 5/18 = 16.66 m/s
• final velocity = v = 45 km/ = 45 × 5/18 = 12.5 m/s
• time = t = 10 s

${\boxed{\sf a=\dfrac{v-u}{t}}}$

$\sf\longrightarrow a=\dfrac{12.5-16.66}{10}$

$\sf\longrightarrow a=\dfrac{-4.16}{10}$

$\sf\longrightarrow a=-0.416$

$\sf R=-(a)$

$\sf\longrightarrow R=-(-0.416)$

$\sf\longrightarrow R=0.416\;m/s^2$